Engine



Dec. 16, 1952 J, P. BUTTERFIELD- ENGINE 5 Sheets-Sheet l Filed Marh 24,1948 JAY J- L BY i /7 7' raam/EVS.

Dec. 16, 1952 J. P. BUTTERFIELD ENG INE Filed March 24, 1948 IN VEN TOR.

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Dec. 16, 1952 l 1 P, BUTTERFlELD 2,621,639

ENGINE Filed March 24, 1948 5 Sheets-Sheet 3 Dc. 16, 1952 J.P.lLn'TEr-zFnlrrallbAV ENGINE 5 Sheets-Sheet 4 Filed March 24, 1948 mwNh Dec- 16, 1952 v J. P. BUTTERFIELD 2,621,639

ENGINE Filed March 24, 1948 5 Sheets-Sheet y M' i C67 7cf .7 iff fa/ vf/2255 f f 9 a-f i 2'/ E /f ym Hrrar/vf/s.

Patented Dec. 16, 1952 UNITED :fs TATfEs PATENT oFFic-E ENGINE.JohnsRfButtereli Grosse Pointe Woods, Mich., .assigner .to -ChryslerCorporation, Highland Park,.Mieh.,.a...corpora.tion.of DelawareApplication'March-Zl, 1948,"Serial No. 165650 (Cl. 12S-56) 6 Claims.

.This application .relates .to engines and 'refers more particularly to.improvements .2in engines .of the double -acting type :having.double-.ended pistons provided with opposed pressure-@receiving n facesat .their opposite ends and .a .crankshaft passing through .thetpistons.

One object vof myinvention is ato .provide an improved intake manifold.for `a doubl'e acting engine.

.Animportantzpurpose .of an engine tof y.this type is :reduction.'insize. vWhen .the ,engine .is small, itiis. a lproblem to nd space`for various accessories that Vmust ibe .attached .to 'the engine.

lI have invente-d .an arrangement .that solves 4the'pro'blem of :spacefor engine zaccessories by .providing a "single Aintake manifold inletfor a `plurality vofV Z.intake :passages .for f the `various icombustion chambers ofthe engine .to Vthereby accomplishal saving inthespaceithat would .otherwise-be Vtaken .up bya multiplicity of inlets.

vAn .object -of :the .present 'invention -is VVto increase theavailablespace for accessories on an engine by providing a single ,inta-kemanifold .inlet to an engine cylinder block gior-a. Jplurality of intakepassages leading to the various com'- .bustion chambers. Thisarrangement is advantageously applied -to -an engine 'in which accessoryspace is 'limited becausexof smallness fof lthe `engine due :to itscomprising .pistons fh'aving iop- .posed 'pressureereceiving Vfaces :attheir :ends and -a crankshaft passing through the` pistons.

.Anotherobject is .to provide animproved water circulating system for adouble acting type 'of engine.

.nfurther .object Vis .to .provide v.a double :acting .engine havingcomponent.interchangeable .cylinider vblock portions.

Other .objects Vare :to :provide .a simple, inovel, and eiiective:system .for .lubricating the :moving partsof :the engine and 'to :drainaway .theexcess lubricant by 'utilizing man-y of the parts :pro- .videdby my .engine construction.

.Other `objects are .to fprovidefa novel .accessory drive l-having.improved utility; also :improvedmeanslfor.admittingllubrcatingoilto'thestorage reservoir or'oi1:.pan.

:Further .objects .and .advantages yof 'my invention twill b'e .moreapparent "from .the following .description of severalembodimentsotmy:invenltion,rreerence being '.made Lto the accompanying.drawingsfin which:

Fig. `1 is a side view'ofian engine block.accord- .ing to the presentinvention;

Fig. 2 isfa plan view'of alpairio'f juxtaposed engine `blocks :withparts broken f-away;

iFig. 3.is afsectional view .taken along the. line 3-3 -of Fig. 12 andshowing the 'cylinder :heads and valve .gear 'of theengin'e;

Fig. '.4 .is a plan view of .a pair .of juxtaposed engine'blocks ofamodfied form;

Fig. .5 .is .a longitudinal .sectional 4elevational .view .approximatelythrough the engine at .the meeting :faces of lthe .cylinder .block.portions showingoneof .theblock portions, a partei .the other. blockportion .being shown vtosillustrate .the oil .pump .and distributerdrive;

Fig. .6 .isla .sectional viewshowing .the oil pump and distributerdrive, .as vgenerally indicated by line 16`6 OfFig. 5.

Reference character ,lil designates component or complementary .engineblocks juxtaposed `so that .cylindrical openings H for pistons arealigned,.as;shown in Fig. 3. Fig. .1 shows that .there are Ytwo.openings II .in each block I0. Mounted Lin feach pair of Yalignedcylindrical opening-s ISI isfadouble-ended piston I2 `having 'pressurefaces I3 at `its opposite ends. Each `piston I21iscomposed ofcomplementary parts I4 havingfskirtprojections I5 labutting on lines I6.The piston parts lf3 lare secured to one another by ourrbolts 'I'f'lvextending through vthe skirts I5 andznuts I8 threadedengagement with-both .ends .of each bolt. .The nuts I8 are-appliedto the ,bolt rendsthrough openings AI9 in the piston skirts. :A crankshaft -2`0 extendsthrough open- .ings -2 I formed inthe .piston I'4 between adjacent'skirtprojections 1.5. vAn `oiiset portion 21a ofthe crankshaft lisffjournalled in :a .slide head 2l formed of complementary parts 2lbsecuredtofgether by bolts.22.y The slidehead parts 25113I :arejournalled in slid'ewa'y portions 23 .formed .onl the ipis'ton partsil.3iso .that the'slide head movesback `and 'forth 'as lviev/.ed in Fig..3, as the .piston I2 reciprocates horizontally, as viewed iin 'the samefgure.

4As seenin Fig. 2, the assembled cylinderblocks im .mate .to .provide acommon intake opening x24, -formedhalfin aLmeeting end face f25a.and2theadjacentzportionof-.a top side or boundary face 1215 biot 'one :blockand the other .half in fia :meeting end :face 25a and .the .adjacentportion l. of .a 'top :side ior boundary iace .250 of .the otheribl'ock. The lower cylinder block, as seen in Fig. 2,-Ihas yamintake.passage .25 .leading from the :common intake L14 '.and terminating in a.seat 2B ifor lan .intake .valve e peratedi'by aispring :opposed .tappetor Lffollower `25d sldablev in 'the guide 21 east-in thezblock..'lhettappetis `operated by fone "-.o'f theillustrated cams125'e'ofrcams'haft-Fztf jour- .inalled fin suitable bearings fitted in thercompan'ion semi-cylindrical openings 25g of the blocks I9. rIhe seat 2Sis in a side 29a at the right side in Fig. 3, at which a cylinder head25h is attached. This cylinder head carries the usual spark plugs 251'and has combustion chambers 257' overlying the adjacent ends ofcylinders il and the intake and exhaust valves for such cylinders. Asseen in Fig. 2, a second intake passage 28 leads from the common inlet24 to an intake valve seat 29 in the side 26a, adapted to cooperate withthe second cylinder in the lower block I of Fig. 2. Similar inletpassages 25 and 28 lead from the common intake 24 to correspondingintake valve seats 29 and 29 in the head side 26h of the upper cylinderblock I9, as viewed in Fig. 2. A second cylinder head 25h is attached tcthe side 2Gb, this cylinder head being like the one aforesaid. Eachblock I0 is provided in its top side 251) and 25e with a half-portion ofa :boss 3I surrounding the common inlet opening 24 against which afitting from a carburetor fuel mixture supply line leading to the inletopening 24 is to be abutted. p The fitting is to be attached to eachportion of boss 3| by means of a screw engaging an opening 32 in eachboss portion.

It will be understood that the right hand block I0 in Fig. 3 (upperblock as viewed in Fig. 2) has, associated with each of its cylinders II and combustion chambers 253i, an intake valve I'25c just like theintake valves for the other block I9.

Each companion half-portion I9 of the cylinder block assembly is formedwith exhaust gas passages and exhaust valve seats for con-ducting theexhaust gas from each of the engine cylinders II. rThus the left handblock I9 of Fig. 3 (lower block as viewed in Fig. 2) is provided withexhaust valve-receiving openings 33 adapted to be fitted withc-onventional valve seat inserts 33'. Each of these openings 33 leadsinwardly and upwardly of this block by a cast exhaust gas passage 34terminating in an opening 35 bounded by a iboss 35a having tappedopenings 35h for receiving fasteners for the conventional flange of thebranch portion of a conventional exhaust manifold (not shown). Thisblock I9 and also the other block (see Fig. 3) has the cast guideways 36for slidably receiving the spring pressed tappets or followers 36aassociated with one of the cams 25e for operating the exhaust valve 35h.As 4indicated by the similar reference characters in the drawings, theright hand block in Fig. 3 has exhaust valve openings and passages justas recited above for the other block and functioning in the same manner.

The blocks I0 have a series of holes or passages 59 extendingtherethrough parallel with the axis of each cylinder II, the holes 50being aligned in the blocks I0 to receive the through-bolt assemblies Iwhich also extend through the cylinder heads 25h and have headed endsseating on the outer faces of these cylinder heads. These bolts `Serveto hold the blocks ID and cylinder heads 2 5h, in assembled relationshipand thus also confine the crankshaft 29, camshaft 25J and partsassoci-ated therewith in their proper operating positions. Additionalbolts 52 pass through the :blocks I9 adjacent the ends of the cylinderheads 25h.

It will be noted that the pairs of intake valve openings 26 and 29 on'opposite sides of blocks `I for the same cylinder II are relativelyoffset from each other in the direction of the axis of the camshaft 251and crankshaft 2|] to accommodate operation of the associated intakevalves by separate cams 25e. Likewise the exhaust v-alves 4since if itbecomes necessary to replace either one of the blocks I9 then this maybe done very economically inasmuch as only one type of block need bekept on hand for service requirements.

Where the blocks I9 are similar to each other as illustrated, each blockhas at its upper face adjacent one end thereof a water or coolantopening 53, 54 bounded by a boss 55 having tapped holes 55 forattachment of a Water pipe so that a coolant may be circulated under theusual pressure to and from the blocks I9 and cylinder heads 25h, one ofthe openings admitting the coolant and the other ejecting it. Thus wateris admitted .at opening 53 whence it iiows in paths provided by coredblock passages 56 and 5l as indicated by the dotted arrows in Fig. 2.

From passage 55 the water passes to .an aligned passage 5S in theadjacent block, a lgasket 59 placed in component half-portions of agroove in the abutting faces of blocks II) preventing leakage of waterinto the cylinder I I. From passages 52 and 5l the water flows throughcored intercommunicating passages 60 surrounding the cylinder portionsII of each block, and through cored passages 6I around the valve guides21 and 39 and around the intake and exhaust passages 25 and 28 to thepassages 62, 53. From passage 53 the water iiows to outlet 54 and frompassage 52 the water flows across the faces of the abutting blocks I0 topassage 64 thence to outlet 54, another gasket 59 effecting a water sealbetween passages 62 and 64.

Each cylinder head 2571. has a cored coolant chamber 55 and wateropenings 66 which register with openings 61 (Fig. 1) in the side faces26a and 29h of blocks I0 so that Water is circulated from the blockpassages G0 and 6I through the cylinder heads. Apart from the waterheaders 55, 5S and 6'2, 64 the water ydoes not cross the face contact25a of blocks I0, one block I9 having a water inlet 53 and the otherhaving the outlet 54.

The blocks I9 are provided with component housing portions providing anenlarged cham- Iber 63, 69 at the opposite ends of the engine. Inchamber 68 there is located the drive 'lo for camshaft 25j from thecrankshaft 29 and in chamber 69 there is located a camshaft drive at IIto a shaft 'I2 extending downwardly to the oil pressure pump I3 in theoil reservoir in pan l-l attached to the bottom of blocks I9 and open tochambers 68 and 69. Shaft 'I2 has an upward extension 'I5 journalled inopening 'It (Fig. 2) in block face 25e for driving a distributor ll. Theopening 'I5 is bounded by a boss 'I8 having the attachment tapped hole19, the primed numerals 16', '18', and I9 indicating the partscorresponding to "I6, 18, and 'I9 for the other block I9. Fitted tob-oss I8 is a breather S9 removable to expose opening 'I6' through whichoil is poured for flow through chamber 68 to the pan l. Various coreopenings 8l in blocks I9 are closed by conventional core plugs or disks82.

The pressurelubrication system comprises the "tion" chambers 'S251'.

aisance@ 'foil pump 13 -`which"draws"lubricantnatits'inlet pipe f t from`pan 1li fand delivers the :oil under 'press-ure upwardly' in thepassage$0 whence the `oil "fiowsby la 'passageiB-'Ito the gallery 83 of that"fblockwhfichfcarries the passage sur and-by vasesof ne -jother Mock.Vnt `"the kfront end fof :the engine the @galleries W3 vfarealso':onnec'ted by fa :passage 9'3 similar to passage @92. 'It-willbefunder-'steoditnat only one vblockportion carries-sheen pulrnp' lilVV although*Where it desired to maintain "nterchangeaiblifty-oi 'block' poftionsilU ,1' thefetlrer liloclr'pc is provided I`tifitlfrthe {sa-me passagesnFig. 6 so `-tna'teitlm'r blockporticn may "he :nttedjwith the cilipnmplana-"used f'to denver f the oil. 9 Such passages as are 'not used in`the par- "ticlr *clock portion that does not carry'thepump mayheieadily 'blocked -foi by suitable plugs ''aft anyfpoints Where' 'theoil pressure 'would otherwise lief-icfst' b'y ywanting the system 'to-the 'oi-l pa-n.

Between the journal portions :'94 "off the caniyshaft "the blockrportions-are Yformed with Ia vearn chamber 9-5 whichaccommodatesoperation:of-the "canrjs e and intdWhich-the'tappet guides'21 and 3f6"op`e^n 'for loil drainage. vv`*I1ie"ca1i'1 chambers-'U85are"formed by mating recesses the yIii-look p0rtions 'attheirrneetingffaces. n

".Fromthe-'galleries83 the 'oil Tis conducted Vby ipassagesel tog-thevarious tappetsz 5d and staand Hby' passages 5 to vthe bearingsforftheLcamshaft journalportions 94. VvExcess lubricant ows 'from Ithese points`or. 'locations into the camrchanibers V95, one *of -Wl'i'ic'h is vaboveeach cylinder bore, -whence the `oil *fldwsfdownwardlythrough y'anopening 8-'6 into each cylinder borethence through 'the'upper'cfthepiston'slideway openings '96, 91 v'and down through 'the hollowcentral chamber portion of eachpiston I2^and then through the 'lowerslideway opening 91 of the piston and through opening '18H0 oil 'pan 14.

Openings 18'6 and'l a'reiforrned by' the mating 'recessed half-portionsin theblocks '|"0 andare Vo'fsuch length'as'toalways communicate vwiththe fing .in tneregion of its Vmili-strcize 'as seen in Fig.

.5. "Thus the 'openings "86,181 necessary to accomniddatethef'sweep -of`th`e bearing b'l'ock`2`l 'are'ut'ilized tofdrain' the "lubricant,It'will be apparent 1 thatthe piston rings "98- 'alwaysseai `theopenings"86,181 "against Vcommunicationwith the combus- Each 'cani -cheminer 95is' in 'constant communication with 'oil pan v14 for oil drainage "at8'6, '596, through the lhollow.' pi'sto'n,

Lbricantfrom one cr 'bothgaueris ys3 'flows under,pressure through thebloc-k .passages 99 lto- ""`the"bear"ings I UD "for the crankshaftendjournals eacrankZ-la and-itsassociated bearingcblock 27|. Fromtli'e:groove |06 -at each crank -bearing cil is supplied-under.pressure-through 'tl-1e bearing- |01 and hearing block portions 2 Ibthroughv passages 108 .to vAluloricate the engaged bearing surfacesbetween block 2 I and piston slideway portions 23.

Excess' lubricant 'from thecrankshaft bearings NIU .isfiree -to drainthrough gopeningsill '.ineadh 'piston fand l'ili'ence through Ithe:piston l-holiow Pcharnilrere'd interior and-down lthroughfopenings91,281 to -oilpan '14. Likewiselubricantrom each crank ournal :andkbearing vlalock land fislideway vdir-airis ."dewnwardlylin rthe.associatedihollowiipistoni tothe oil pan.

4 `-dia'graniin'atically .shows a modified engine .i 'which Aeach of two.mating blocks has 'formed therein 'halffo 'an intake manifold vinletopemng f' stitcrmedat its. meeting l faces@ which raref-als'o "themeeting faces' of the'ftopside's 39a of the blocks 3 1 'fan-d halfofifaninlet'rh'eaider passage `r4'0 from which exte'nd -Sfourni'el niiet"ieranch passages 114i! -in .each `"block-237. -.Each mel `inletl'passage 'terminates ...in a seat 41" for ian intake ffvalve scm'asi'dey"42' fof la lolock 5311itoivhich la cylinderheadfis to loe-attached.Eachfblokl has a cylinder similar to thefTFig. .l1 .zembodimait tor yeach lof 'tl-ie I'four inlet .branch passages :4 l. 4hEachcylinder'islserved byzan inlet .branch 'passage `d4l offeachlislockl.lThe engine -isiof the .type shown in'Figb3," in which the .pistonpressure .faces at hoth yends and the crankshaft .extends through fthepi'st'on. A rhali` 'portion -foffloossf is' torn-led on yeachfl'olock 31around the opening '38 ias-"iin Fig. 3 and' isladapted'lto he abuttedfhy'the' aforesaid hiel' mixture Jsupply` line. LOpenmgs "44 in'Ithefbosses lare to' be engaged by screws :fastenin'g 'the inl-,ting to:the-bosses :as :for Fig. '-2. "In *each 'block `il there are Ifourexhaust .outlet openings 245 from which extend "passages '4B '5to 'seats4B" iforv..exhaust valves in the head fsidef42 similar 'tothe Fig. T2arrangement. Each-outlet 45 is surrounded hy-2a' boss 541, which is'to'receive in abutting relation'a '-fitting enla-n exhaust 'mani-- `foldyof conventionaltype held agains'tl-'theboss iby screwsengagingiopeningsd in the boss 247. -Thebloc'ks- '31 varecorecl vforWater'circulation and, -apart from the l'di-'fferences 'in the intakeandlexhaust gas Vpassages, are 4vconstructed ysimilarly to kthe blocks ofthe principal embodiment, "Fig. 4-"being a"diagrammaticshowing i-nwhichfthe details have lbeen omitted.

YFeatures "of Vnovelty disclosed in the subject 'application but notlaimed Iherein are 'moreparticularly describedand claimed in thecopending application V-of 'Alexander G. Herresh'ofh 'Serial No.A.l'ij801iiled March '24, '1948, inmy lcopendng -applicationsfSerial"Nos:16 ,"645, 156,646; '16,648fand 16,2649 iil'ed March 24,1948, and PatentNo. "2,571,1198.

claim:

l. '.Incoznbination, a cylinder block comprising a 'pair4ofe'nginehlocks held together and having endia'ces meeting `one'another in a plane extending longitudinally Yof the engine,-veach'block ,having "openings "for pistons extending generallytransversely "to its'm'eeting end face and inalignvnient withcorresponding 'openings 4forpistdns "in,

Vthe 'other block, eachhlock 'having interiorlyidisposed 'fuel "intakepassages 'or' the lplurality l"of piston'openings in'tha't block.branching lout from 'a common exteriorly disposed, sectionalizedcav-.fity formed adjacent 'one side of andl inthe' meetving'en'd face ofthat'b1ock,'the common'cavitysec- 'tions 'in the end faces of the blockscooperating tofform a common 'inlet for thesaid intake" passages in 'oneblock-'and the 'said intake `'passages `in the votl'i'er block.

v V2. A cylinder 4block 1structure for an engine of the. opposedftypecomprising, in combination, a1 "pair "olf blocks Vextendinglongitudinallyl 'i the engineand adapted tope-secureditogether inV ltacecontact relationship, said block structure having a plurality ofcylinders each having a component portion thereof extending transverselythrough one of said blocks, each of said blocks having a pair of intakeand exhaust valve-receiving openings in an outer boundary face thereofadjacent -an end of each of said component cylinder portions, said blockstructure having an outer boundary face disposed transversely of saidblock faces and having component face portions thereof on each of saidblocks, said blocks being formed with passage means for conductingexhaust gas from said exhaust valve-receiving openings to saidtransversely disposed face of the block structure,

4said transversely disposed face having an intake gas opening componentportions of which are formed in each of said component face portions,each of said blocks having intake gas conducting passages thereinbetween said intake gas opening and said intake valve-receiving opening.

3. A cylinder block structure for an engine of the opposed typecomprising, in combination, a pair of blocks extending longitudinally ofthe engine and adapted to be secured together in face contactrelationship, said block structure having a plurality of cylinders eachhaving a component portion thereof extending transversely through one ofsaid blocks, each of said blocks having a pair of intake and exhaustvalve-receiving openings in an outer boundary face disposed trans-.versely of said block faces and having component face portions thereofon each of said blocks, each of said component face portions beingprovided with a plurality of exhaust gas openings and a componentportion of an intake gas opening, each of said blocks having passagemeans formed therein for placing said intake gas opening incommunication with said intake valve-receiving openings of said blocksand each of said blocks khaving other passage means for placing its saidexhaust valve-receiving openings respectively in communication with itssaid exhaust gas openings.

4. A cylinder block structure for an engine of the opposed typecomprising, in combination, a pair of cylinder blocks extendinglongitudinally of the engine and adapted to be secured together in facecontact relationship along an inner end face thereof, said blockstructure having a plurality of cylinders each having a componentportion thereof extending ytransversely through one of said blocksnormal to said contacting inner end faces, each of said blocks having apair of intake and exhaust valve-receiving openings in an outer end facethereof adjacent an end of each of said component cylinder portions, theintake valve-receiving openings adjacent opposite ends of thesainecylinder being offset With respect to one ano-ther in a directionlongitudinally of the engine. the exhaust valve-receiving openingsadjacent opposite ends of the same cylinder being offset with respect toone another and with respect to said intake valve receiving openings ina direction longitudinally of the engine, said block structure having anouter boundary face disposed transversely of said block end faces andhaving component face portions thereof on each of said blocks, saidblocks being formed with integral passage means for conducting exhaustgas from said exhaust valve-receiving openings to said transverselydisposed boundary face of the block structure, said transverselydisposed boundary f ace having an intake gas opening component portionsof which are formed in each of said component contacting, end faceportions, each of said blocks having integral intake gas conductingpassages therein extending between said intake gas opening and saidintake valve-receiving opening.

5. A cylinder block structure for an engine of the opposed typecomprising, in combination, a pair of cylinder blocks extendinglongitudinally of the engine and adapted to be secured together in facecontact relationship along an inner end face thereof, said blockstructure having a plurality of cylinders each having va componentportion thereof extending transversely through one of said blocks normalto said contacting inner end faces, each of said blocks having a pair ofintake and exhaust valve-receiving opening in an outer end face thereofadjacent an end of each of said component cylinder portions, the intakevalve-receiving openings adjacent opposite ends of the same cylinderbeing offset with respect to one another in a direction longitudinallyof the engine, the exhaust Valve-receiving openings adjacent oppositeends of the same cylinder being offset with respect to one another `andwith respect to said intake valve receiving openings in a directionlongitudinally of the engine, said block structure having an outer f'boundary face disposed transversely of said block end faces and havingcomponent face portions thereof on each of said blocks, each of saidcomponent boundary face portions being provided with a plurality ofexhaust gas openings within the periphery thereof and a componentAportion of an intake gas opening along the inner end face edge thereof,each of said blocks having integral passage means formed therein forplacing said intake gas opening in communication with said intakevalve-receiving openings of said blocks, said intake gas passage meanscomprising a common header passage in the block inner end face extendinglongitudinally of the block and a plurality of branch passages extendingtransversely from the header passage to each of the intake valvereceiving openings, and each of said blocks having other integralpassage means for placing one of said exhaust valve-receiving openingsrespectively in communication with one of said exhaust gas openings.

6. In an engine of the double Vacting type comprising, in combination, acylinder block structure comprising component block portions havingopposed end faces brought together in face contact in a plane extendinglongitudinally of the engine, said block structure having Ia pluralityof cylinders extending transversely of said plane and opening atopposite sides of said structure, each of said cylinders havingcomponent portions thereof formed in said block portions andcommunicating with each other at said plane of face contact, `adouble-ended piston structure operable in each of said cylinders, acylinder head structure mounted on each of the exposed end faces of saidblock structure, a crankshaft mounted in said block structure andextending transversely through each of said pistons, a camshaft mountedin said block structure and driven from said crankshaft for rotationyabout an axis parallel with the axis of said crankshaft, each of saidblock structures having pairs of component openings formed in theircontacting end faces for respectively rotatably mounting said crankshaftandz camshaft, each of said block portions having a pair of intake andexhaust valve-receiving openings in the exposed end faces thereofadjacent an end of each of said cylinders, intake and exhaust valvesrespectively operably disposed in said intake and exhaustvalve-receiving openings, means operably connesting said valves withsaid camshaft, each of said block portions having a boundary faceextending transversely between the block end faces and provided with a,plurality of exhaust gas openings therein, and .a component portion ofan intake opening formed in the block inner end face and arranged toprovide a common opening for fuel supply to the pistons each of saidblock portions having interiorly disposed exhaust gas passages formedtherein and respectively disposed to extend between its said exhaustvalvereceiving openings and its said exhaust gas openings, each of saidblock portions having interior passage means formed therein forconducting intake gas from said common fuel intake opening to its saidintake valve-receiving openings.

J OHN P. BUTTERFIELD.

REFERENCES CITED The following references are of record in the le ofthis patent:

Number 10 UNITED STATES PATENTS Name Date Swain Aug. 8, Twombly Feb. 27,Tomasini Feb. 16, Sharpneok et al. May 18, Kenyon Feb. 13, Salway Jan.22, Tietzmann Dec. 17, Bosmans Apr. 30, Woolson Apr. 12, Snyder Apr. 3,Irgen Apr. 23, Swan July '7, Greene Sept. 21, Klotsoh Mar. 28, DomanJuly 18, Stubings Aug. 22, Herrmann May 27, Herrmann May 27, Molina Aug.18, Edmunds Jan. 4,

